fix: You must call removeView()

11-02 11:43:53.235: E/AndroidRuntime(3670): Caused by: java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
11-02 11:43:53.235: E/AndroidRuntime(3670): 	at android.view.ViewGroup.addViewInner(ViewGroup.java:3618)
11-02 11:43:53.235: E/AndroidRuntime(3670): 	at android.view.ViewGroup.addView(ViewGroup.java:3489)
11-02 11:43:53.235: E/AndroidRuntime(3670): 	at android.view.ViewGroup.addView(ViewGroup.java:3465)
11-02 11:43:53.235: E/AndroidRuntime(3670): 	at net.simonvt.menudrawer.MenuDrawer.setMenuView(MenuDrawer.java:1552)
11-02 11:43:53.235: E/AndroidRuntime(3670): 	at net.simonvt.menudrawer.MenuDrawer.setMenuView(MenuDrawer.java:1536)